The present invention relates to a method and a device for manufacturing heat exchanger elements with a tubular base body, having in cross-section a width that is substantially greater than its height and being provided at its surface with ribs that increase the heat exchanging surface area, and also relates toga tubular member produced by the inventive method and device.
Such tubular members as well as methods and a device for their manufacture are known from European Patent Application 0 546 334. According to the disclosure, on oppositely arranged wide sides of the base body profile a corrugated sheet metal strip is applied respectively in the longitudinal direction of the base body, whereby the corrugated sheet metal strips are removed from a roll and folded, respectively, corrugated before being applied to the base body. After being pressed onto the surface of the base body the corrugated sheet metal strips are connected to the base body at least at some contact locations whereby the base body together with the corrugated sheet metal strips is continuously moved in the longitudinal direction of the base body relative to a fastening device.
In the known method the specifications with respect to dimensioning of the closed tubular body are to remain within very narrow limits because it must be ensured that during attachment of the folded or wave-shaped corrugated sheet metal strips a gap-free contact is provided for the fastening process. The stiffness of the folded or wave-shaped corrugated sheet metal strips is so high that a deformation of the corrugated strips for adaptation to the base body, which is manufactured with greater tolerances, is impossible. For this reason, in the known method only precisely manufactured and thus very expensive base bodies can be used.
It is therefore an object of the present invention to improve the known method, the corresponding device and the resulting tubular member such that inexpensively manufactured base bodies with a great width and a small height can be used for attaching thereto the corrugated sheet metal strips .